Genetically-engineered tomato. Conceptual image of a tomato in a cage or molecule-like structure, emerging from water. In the background are strands of DNA (deoxyribonucleic acid). This image may depict the concept of genetically-engineered food where DNA is introduced into the tomato's genes. Genetic engineering makes it possible to introduce DNA into an organism that may have originated in an entirely different species. This is impossible to achieve by conventional breeding. The DNA may make the tomato resistant to fungal moulds, or enable the fruit to ripen on the plant without softening which improves its flavour.